Telephone system.



F.-M. SLOUGH.

TELEPHONE SYSTEM.

APPLICATION FILED JULY 24, 1912 1,1 92,007, Patented July 25, 1916 Wifnesses In venfol FfiHA/fl' M. Slough Au 5 .0 W W m: non/us PETERS cayummuma, wnsnmarou, n c

rn STATES PATENT OFFICE;

FRANK M. SLOUGI-I, 01E ELYRIA, OHIO, ASSIGNOR TO :THE GARFORD MANUFACTURING COMPANY, OF ELYBIA, OHIO, A CORPORATION OF OHIO.

TELEPHONE SYSTEM.

Specification of Letters Patent.

Application filed July 24, 1912. Serial No. 711,194.

To all whom it may concern:

Be it known that I, FRANK M. SLoUGH, a citizen of the United States, residing at Elyria, in the county of Lorain and State of Ohio, have inventedcertain new and useful Improvements in Telephone Systems; and I do hereby declare the following to be a full, clear, and exact description of an embodiment of the invention, such as will enable others skilled in the art to which the invention appertains to make and use the same.

The invention relates to telephone systems, and more particularly to common battery central station systems of what is known as the manual type. In such systems it is common to provide,preferably at the central station, a telephone set for an attendant who usually attends to the duty of connecting the telephone lines together. This attendants set is adapted to be connected to the cord circuit or other means employednfor connect ing the telephone lines together, or to be otherwise associated with the telephone lines in such a way as to enable the attendant to communicate with the subscriberupon the lines. As the attendants set is provided especially for the purpose of enabling the operator to ascertain the connection desired, it will be apparent that'there is no reason why the operator should place herself in communication with the subscribers after such connection is made. On the contrary,

it is desirable that she should beeXcluded not only to prevent her interrupting a conversation or eavesdropping, but because of the fact that manysubscribers claim that the operator has interrupted their conversation or listened in when she has not done so,

registering kicks to the manager to that carry on a conversation regarding private matters with the assurance that nobody can listen in upon them.

Other objects ofmy invention,the invention itself and the objects thereof will be I H. Of course, this may consist of any wellknown form of substation set. The substation set at B is connected by a telephone, line 12 to a jack J at the main station, the ]&(3k being preferably mounted in the switchboard. At the substation O, which I a shall call the called subscribers station, I show a set including a transmitter T, receiver R and a switch hook N. The substation set C is connected by a line, here shown composed of the conductors 3 and 4,

to the main station A where it terminates 7 preferably in the jack J upon the switchboard. At the main station A I provide means for connecting the telephone lines together, the means here shown, consisting of a cord circuit having two strands 5 and 6, a condenser 7 interposed in the strand 5 and a condenser 8 'lIliZGIPOSQCl in the strand 6.

These strands connect with some connecting means adapted to cooperate with the terminals of the lines for connecting them together through the cord circuit. In the form shown, an answering plug P and a calling plug P are used for this purpose, the

plug P adapted to cooperate with the jack J and the plug P with the jack J. At E I show the operators telephone set, which may be connected by any suitable means, such as a listening key K and conductors 9 and 10 to the cord circuit. the listening key K the 'operators set will be connected into; the cord circuit. In the form shown, the listening key and the conductors 9 and 10 thus constitute means for permitting the connection of the operators set to the cord circuit. At F I show means under the control of the called'subscriber for automatically interrupting the connection of the operators set, to the cord circuit and By operating this may take place when the called subscriber responds. In the form shown, this consists of a relay F which when once energized is locked up, preventing the reconnection of the operators set to the cord circuit during the conversation. In fact, in Fig. 1 it would be necessary to remove the calling plug P before the locking circuit will be broken.

The apparatus and its objects will probably. be better understood from a description of the operation. Suppose that the subscriber at B desires to converse with the subscriber at C: the receiver R is removed, whereupon the switch hook H rises and engages the contact 11, completing a circuit through the calling relay 12 as follows ground at 13-battery 14- relay 12-15 16-171T1lH-2-181920 to ground at 21. The relay at 12 will be energized attracting its armature 22, closing the switch 2223 and completing a circuit through the calling lamp '24: as follows ground 13- battery 1 t222324.

ground at 25. This lamp is mounted in a place suitable for attracting the operator when the lamp is lighted. Seeing the lamp burning, the operator inserts the calling plug P into the jack J, the tip 26"engaging the tip spring 27 and the sleeve 28, engaging the sleeve spring 29 and the ring 30, completing a circuit through the answering sleeve supervisory relay 31 and'the cut-off relay 32 as follows :ground 33-34. battery 35 relay 31 sleeve strand 6 of the cord 2830-3220- to ground at 21. The relays 31 and 32 will be energized, the relay 32 attracting the armatures 15 and 19 and cutting on the line lamp and relay from the line and extinguishinbg the line lamp. The relay 31 attracts its armature 10, closing a switch t041 which would complete a circuit through the answering supervisory lamp as were not the answering tip supervisory relay l3 energized at the same time.

Owing to the fact that the calling subscriber is on the line, the circuit through this line will include the battery 35, the

relays 43 and 31, the two strands of the cord, the plug and jack contacts, the two limbs of the line and the calling subscribers substation set. The operator then operates the key K, which as explained, will connectthe operators set to the strands of the cord circuit through the conductors 9 and 10.

Having learned that the subscriber at C is called, the operator, after testing the line by meansnot shown, inserts theplug P into the jack J, completing a circuit through the cut-off relay 50 and the calling supervisory relay 51 through the battery 35. Both the relays 50 and 51 will be energized, the former cutting off the called line relay and lamp and the latter attracting its armature 52 and completing a circuit through the calling supervisory lamp 53 as follows :ground 333l35 5752 58596053 to ground at 61. This lamp will be lighted and will remain lighted until the called subscriber responds. When the called subscribed responds, the switch hook N will engage its upper contact 62, completing a circuit through the tip supervisory relay 63 as follows :-N3

7156335 5 1-65 6-724D' -62. The relay 63 will be energized, attracting its armature 59 to engage the back contact 80 and complete a circuit through the relay F as follows :33-3435 57 5258598081F to ground at 82. The relay F will attract the armatures 83 and 841, cutting off the operators set from the cord circuit and attracting the armature 90, closing the switch 91 of a lockmg circuit, thereby preventing a reconnection of the operators set during the conversation. This locking circuit is traced as as follows :82F91909258-52 This circuit will not be opened until the plug P is Withdrawn from the jack J, thus'interrupting the connectlon between the cord circuit and the called subscribers line. When this is done, the relay 51 will be deenergized, and the calling end of the cord restored to normal.

In the form shown in Fig. 2, the relay will be operated when the called subscriber responds through the switch 101- the battery 102 and the relay 103. This relay will attract the armatures 104: and 105 interrupting the connection between the operators set and the cord circuit at 106, completing a locking circuit through its other ground at 107 108 100 101 105 109 -110 through the battery 102, back to ground 107, making the relay independent of the called subscriber after such subscriber has answered. The relay 120 will be energized when the switch 121 is closed, pulling up its armature 122, interrupting the circuit of the calling'supervisory signal 123. When the called subscrlber hangs up and the operator withdraws the calling plug, the apparatus 'in the calling end of the cord will be reof my invention, these embodiments having 7 been shown merely for the purpose of illustrating specific embodiments thereof.

1. In a telephone system, the combination of a main station, a plurality of substations,

telephone lines extending from said substations to said main station, connecting means at the main station for connecting said telephone lines'together, a pair of supervisory relays in the calling end of said connecting means, an operators set at said main station and means controlled by the joint action of said relays controlling the connection of said operators set to said connecting means. a

2. In a telephone system, the combination of a main station, a plurality of substations, means at the main station for connecting such telephone lines together, a calling sleeve supervisory relay at the main station, an operatorsset at the main station, means for connecting said operators set to said connecting means and locking apparatus for locking said operators set connecting means, such operators set connecting means being under the joint control of the calling sleeve supervisory relay and the called subscriber.

3. In a telephone system, the combination of a main station, a plurality of substations, telephone lines for connecting said stations together, means at the main station for connecting said telephone lines together, an operators set at the main station and means under the control of the called subscriber for connecting said set to said connecting means and a device for automatically removing such control from the called subscriber after the called subscriber has responded.

.4. In a telephone system, the combination of a main station, a plurality of substations, telephone lines connecting said main and substations, link conductors to connect said telephone lines together, an operators set, means to connect said set to said link conductors, means including a portion of thetalking circuit for disconnecting the operators set from such link conductors and locking apparatus for said last named means.

5. In a telephone system, the combination of a main station, a plurality of substations, telephone lines connecting said main and substations, a cord circuit at the main station for connecting said lines together, an operators set at the main station and means to connect said set to the cord, electro-magnetic means controlled by the called subscriber for interrupting the connection of the operators set to the cord circuit and locking means for such electro-magnetic means.

6. In a telephone system, the combination of a main station, a plurality of substations, telephone lines for connecting said substations to said main stations, a cord circuit at the main station for connecting the telephone lines together, an operators set at the main station adapted to be connected to the cord circuit, means for automatically disconnecting the operators set from the cord circuit when the called subscriber responds, and means for preventing the reconnection of the operators set to the cord until the cord has been disconnected from the called subscribers line.

7 In a telephone system, the combination of a main station, a plurality of substations, telephone lines for connecting said main and substations, a cord circuit at the main station for connecting said telephone lines together, tip and sleeve supervisory relays in said cord, an-operators set at the main station adapted to be connected to the cord circuit, a relay controlling the connection of the set to the cord, a circuit for such relay controlled by the tip supervisory relay and a locking circuit for said relay controlled by the sleeve supervisory relay.

8. In a telephone system, the combination of a main station, a plurality of substations, telephone lines for connecting said substations to said main station, a cord circuit at the main station, an operators set, means permitting the connection'of the operators set to the cord circuit during the setting up of a connection and until the response of the called station and means to prevent the connection of the set to the cord after the called station once responds.

9. In a telephone system, the combination of a plurality of stations, one of which at least is an intermediate station, means to connect two of said stations together in conversational circuit, an attendants set at the intermediate stat-ion, means to connect the attendants set to the conductors of such conversational circuit and means to lock the attendants set from such conversational circuit after such circuit is completed, said locking means acting to exclude the attendants set until the calling plug is withdrawn. a

10. In a telephone system, the combination of a plurality of stations, one of which is an intermediate station, means to connect two of said stations together in conversational circuit, an attendants set at the inter mediate station, means to connect the attendants set to the conductors of such conversational circuit, means under the control of the called subscriber for disconnecting said set from such circuit and means to remove such means from the control of said subscriber, said last named means also acting to exclude said attendants set from said circuit.

In testimony whereof, I afliX my signature, in the presence of two witnesses.

FRANK M. SLOUGH. Witnesses:

D. A. GLovER, F.-O. RroHnY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

